scholarly journals Acclimation of Tobacco Leaves to High Light Intensity Drives the Plastoquinone Oxidation System—Relationship Among the Fraction of Open PSII Centers, Non-Photochemical Quenching of Chl Fluorescence and the Maximum Quantum Yield of PSII in the Dark

2009 ◽  
Vol 50 (4) ◽  
pp. 730-743 ◽  
Author(s):  
Chikahiro Miyake ◽  
Katsumi Amako ◽  
Naomasa Shiraishi ◽  
Toshio Sugimoto
Keyword(s):  
Quantum Yield ◽  
Light Intensity ◽  
High Light Intensity ◽  
High Light ◽  
Photochemical Quenching ◽  
Maximum Quantum Yield ◽  
Non Photochemical Quenching ◽  
Quantum Yield Of Psii ◽  
Oxidation System ◽  
Chl Fluorescence

scholarly journals An optimised method for correcting quenched fluorescence yield

2014 ◽  
Vol 11 (3) ◽  
pp. 1243-1264 ◽  
Author(s):  
L. Biermann ◽  
C. Guinet ◽  
M. Bester ◽  
A. Brierley ◽  
L. Boehme
Keyword(s):  
Light Intensity ◽  
Southern Ocean ◽  
Fluorescence Emission ◽  
Euphotic Zone ◽  
Fluorescence Yield ◽  
High Light Intensity ◽  
High Light ◽  
Photochemical Quenching ◽  
Non Photochemical Quenching

Abstract. Under high light intensity, phytoplankton protect their photosystems from bleaching through non-photochemical quenching processes. The consequence of this is suppression of fluorescence emission, which must be corrected when measuring in situ yield with fluorometers. Previously, this has been done using the limit of the mixed layer, assuming that phytoplankton are uniformly mixed from the surface to this depth. However, the assumption of homogeneity is not robust in oceanic regimes that support deep chlorophyll maxima. To account for these features, we correct from the limit of the euphotic zone, defined as the depth at which light is at ~1% of the surface value. This method was applied to fluorescence data collected by eleven animal-borne fluorometers deployed in the Southern Ocean over four austral summers. Six tags returned data showing evidence of deep chlorophyll features. Using the depth of the euphotic layer, quenching was corrected without masking subsurface fluorescence signals.

scholarly journals Intoxication and Physiological Aspects of Forage Plants and Weeds Submitted to Clomazone Atmospheric Waste

2018 ◽  
Vol 36 (0) ◽  
Author(s):  
M.M. SILVA ◽  
J.B. SANTOS ◽  
E.A. SANTOS ◽  
M.V. SANTOS ◽  
L.T. SARDINHA ◽  
...  
Keyword(s):  
Quantum Yield ◽  
Plant Species ◽  
Photochemical Quenching ◽  
Maximum Quantum Yield ◽  
Physiological Variables ◽  
Fluorescence Maximum ◽  
Fodder Plants ◽  
Urochloa Brizantha ◽  
Non Photochemical Quenching ◽  
Quantum Yield Of Psii

ABSTRACT: Herbicide volatilization may generate environmental and agricultural problems and result in visual or physiological contamination of non-target plant species. Thus, the goal of this research was to study the fluorescence of chlorophyll a in weeds and fodder plants under the effect of clomazone in the form of atmospheric waste. The experiment was conducted under field conditions designed in randomized blocks with four replications, in a 6 x 4 factor scheme, with six plant species: Dolichos lablab, bicolor Sorgum, Urochloa brizantha, Macrotyloma axillare, Portulaca oleracea and Sida rhombifolia. There were four solutions containing 0, 360, 720 and 1,080 g ha-1 of clomazone (0, 0.05, 0.10 and 0.15 mg L-1, considered as the volume). Seedbeds were built and covered with transparent polyethylene film of 150 μm, with a volume of 12 m³. Fodder plants were sown in line, while weeds were selected according to the incidence. On the sixteenth day after emergence, concentrations of herbicide diluted on three petri dishes were inserted. After 72 hours of exposure, the tunnels were opened and the dishes were removed, noticing evaporation of the product. The following evaluationswere performed: plant poisoning, initial fluorescence, maximum quantum yield of PSII, photochemical quenching, non-photochemical quenching and chlorophyll content. Even at concentrations that do not promote visual effect, clomazone can cause significant damage in the photosynthetic activity of the species. The physiological variables chlorophyll, maximum quantum yield of PSII and initial chlorophyll fluorescence can be effectively used to monitor clomazone waste in the atmosphere.

Acquired tolerance of the photosynthetic apparatus to photoinhibition as a result of growing Solanum lycopersicum at moderately higher temperature and light intensity

2019 ◽  
Vol 46 (6) ◽  
pp. 555 ◽  
Author(s):  
Milena T. Gerganova ◽  
Aygyun K. Faik ◽  
Maya Y. Velitchkova
Keyword(s):  
High Temperature ◽  
Quantum Yield ◽  
Light Intensity ◽  
Electron Flow ◽  
Photosynthetic Apparatus ◽  
High Light ◽  
Cyclic Electron Flow ◽  
Photochemical Quenching ◽  
Kinetics Of ◽  
Moderately High Temperature

The kinetics of photoinhibition in detached leaves from tomato plants (Solanium lycopersicum L. cv. M82) grown for 6 days under different combinations of optimal and moderately high temperature and optimal and high light intensity were studied. The inhibition of PSII was evaluated by changes in maximal quantum yield, the coefficient of photochemical quenching and the quantum yield of PSII. The changes of PSI activity was estimated by the redox state of P700. The involvement of different possible protective processes was checked by determination of nonphotochemical quenching and cyclic electron flow around PSI. To evaluate to what extent the photosynthetic apparatus and its response to high light treatment was affected by growth conditions, the kinetics of photoinhibition in isolated thylakoid membranes were also studied. The photochemical activities of both photosystems and changes in the energy distribution and interactions between them were evaluated by means of a Clark electrode and 77 K fluorescence analysis. The data showed an increased tolerance to photoinhibition in plants grown under a combination of moderately high temperature and light intensity, which was related to the stimulation of cyclic electron flow, PSI activity and rearrangements of pigment–protein complexes, leading to a decrease in the excitation energy delivered to PSII.

scholarly journals Both Multi-Segment Light Intensity and Extended Photoperiod Lighting Strategies, with the Same Daily Light Integral, Promoted Lactuca sativa L. Growth and Photosynthesis

Agronomy ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 857 ◽  
Author(s):  
Hanping Mao ◽  
Teng Hang ◽  
Xiaodong Zhang ◽  
Na Lu
Keyword(s):  
Quantum Yield ◽  
Light Intensity ◽  
Plant Growth ◽  
Light Stress ◽  
Photochemical Quenching ◽  
Daily Light Integral ◽  
Weak Light ◽  
Research On Application ◽  
Non Photochemical Quenching ◽  
Light Integral

With the rise of plant factories around the world, more and more crops are cultivated under artificial light. Studies on effects of lighting strategies on plant growth, such as different light intensities, photoperiods, and their combinations, have been widely conducted. However, research on application of multi-segment light strategies and associated plant growth mechanisms is still relatively lacking. In the present study, two lighting strategies, multi-segment light intensity and extended photoperiod, were compared with a constant light intensity with a 12 h light/12 h dark cycle and the same daily light integral (DLI). Both lighting strategies promoted plant growth but acted via different mechanisms. The multi-segment light intensity lighting strategy promoted plant growth by decreasing non-photochemical quenching (NPQ) of the excited state of chlorophyll and increasing the quantum yield of PSII electron transport (PhiPSII), quantum yield of the carboxylation rate (PhiCO2), and photochemical quenching (qP), also taking advantage of the circadian rhythm. The extended photoperiod lighting strategy promoted plant growth by compensating for weak light stress and increasing light-use efficiency by increasing chlorophyll content under weak light conditions.

Nitrogen Fixation on a Tropical Volcano, La Soufrière (Guadeloupe): The Interaction of Temperature, Moisture, and Light with Net Photosynthesis and Nitrogenase Activity in Stereocaulon Virgatum and Response to Periods of Insolation Shock

1988 ◽  
Vol 20 (1) ◽  
pp. 63-81 ◽  
Author(s):  
R. P. Fritz-Sheridan ◽  
D. S. Coxson
Keyword(s):  
Quantum Yield ◽  
Light Intensity ◽  
Acetylene Reduction ◽  
Light Exposure ◽  
Nitrogenase Activity ◽  
Dark Respiration ◽  
Net Photosynthesis ◽  
High Light Intensity ◽  
High Light ◽  
Apparent Quantum Yield

AbstractThe response of net photosynthesis, dark respiration and acetylene reduction to temperature, moisture and light intensity were examined for Stereocaulon virgatum growing in the cloud/shroud zone on the tropical volcano La Soufrière, Guadeloupe, French West Indies. Rates for both acetylene reduction and net photosynthesis were maximal at saturating water contents, a pattern attributed to the finely branched nature of the phyllocladoid branchlets and the exposed position of spherical cephalodia, both of which minimize the formation of surface and interhyphal water films. Under conditions typical of those during cloud/shroud periods (13–16°C), thalli of S. virgatum exhibit many characteristics seen in other shade-tolerant lichen species. Net photosynthesis was light saturated at 300 μmol m−2 s−1 PAR, while the photocompensation point was less than 25 µmol m−2 s−1 PAR. Net photosynthetic uptake of carbon dioxide was optimal at 27–34°C, at which point light saturation was near 700 µmol m−2 s−1 PAR and the photocompensation point between 50 and 100 µmol m−2 s−1 PAR. Thalli of S. virgatin exhibited temperature-dependent sensitivity to high insolation. Only at 20°C were thalli able to tolerate high light exposure without reduction of apparent quantum yield. Exposure to high light intensity at 40°C inhibited the apparent quantum yield by almost 40% and acetylene reduction by 95%. This suggests brief periods of insolation shock may exert an influence disproportionately higher than either their frequency or duration. Thalli are normally exposed to cloud/shroud conditions but net photosynthetic uptake was maximal only during periods of elevated thallus temperature experienced at the onset of an insolation shock. However, with prolonged high insolation exposure and further elevation of thallus temperatures and thallus desiccation, severe impairment of subsequent photosynthetic activity ensues. S. virgatum may be characterized as a shade-tolerant species but its physiology is more adapted in some respects to conditions experienced during rare periods of full insolation.

scholarly journals Effects of Light Intensity on Cyclic Electron Flow Around PSI and its Relationship to Non-photochemical Quenching of Chl Fluorescence in Tobacco Leaves

2005 ◽  
Vol 46 (11) ◽  
pp. 1819-1830 ◽  
Author(s):  
Chikahiro Miyake ◽  
Sayaka Horiguchi ◽  
Amane Makino ◽  
Yuki Shinzaki ◽  
Hiroshi Yamamoto ◽  
...  
Keyword(s):  
Light Intensity ◽  
Electron Flow ◽  
Cyclic Electron Flow ◽  
Photochemical Quenching ◽  
Tobacco Leaves ◽  
Non Photochemical Quenching ◽  
Chl Fluorescence

scholarly journals Roles of OsSOQ1 in photoprotection and fatty acid metabolism of rice

2021 ◽  
Author(s):  
Zhen-Hui Kang ◽  
Yang Gou ◽  
Qi-Rui Deng ◽  
Zi-yu Hu ◽  
Guan-Rong Li
Keyword(s):  
Fatty Acid ◽  
Light Intensity ◽  
Fatty Acid Metabolism ◽  
Acid Metabolism ◽  
Function Analysis ◽  
Photochemical Efficiency ◽  
High Light Intensity ◽  
High Light ◽  
Redox Activity ◽  
Photochemical Quenching

Abstract Presented here is the function analysis of a homolog of Arabidopsis SOQ1, OsSOQ1 in rice. Homozygous mutants (ossoq1) were obtained by CRISPR/Cas9 to knockout OsSOQ1. The mutants showed significant lower plant height, tiller number, panicle length, effective panicle, and grain number per panicle compared to the wild-type (WT). Western blot analysis showed that OsSOQ1 is a thylakoid membrane protein, with the thioredoxin-like (Trx-like) domain facing the lumen. Loss of OsSOQ1 did not significantly affect the protein level of photosystem II (PSII) subunits, but down-regulated the content of a non-photochemical quenching (NPQ) player PsbS, resulting in a low NPQ under high light intensity in the mutant. UPLC-MS/MS experiments showed that OsSOQ1 is involved in the fatty acid biosynthesis pathway of rice. The Trx-like domain possessed redox activity in vitro as shown by insulin assay; and in the yeast two-hybrid experiment, it was found that the Trx-like domain interacted with the chloroplast lipocalin OsLCNP, which usually binds lipid molecules. These findings revealed that the role of OsSOQ1 is to maintain the photochemical efficiency of PSII under high light intensity and regulate fatty acid metabolism in rice.

Characteristics of Photosynthesis in Different Wheat Cultivars under High Light Intensity and High Temperature Stresses

2009 ◽  
Vol 34 (12) ◽  
pp. 2196-2201 ◽  
Author(s):  
Xue-Li QI ◽  
Lin HU ◽  
Hai-Bin DONG ◽  
Lei ZHANG ◽  
Gen-Song WANG ◽  
...  
Keyword(s):  
High Temperature ◽  
Light Intensity ◽  
High Light Intensity ◽  
High Light ◽  
Wheat Cultivars ◽  
Temperature Stresses

Light Absorption and Partitioning in Response to Nitrogen in Apple Leaves

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 541a-541
Author(s):  
Lailiang Cheng ◽  
Leslie H. Fuchigami ◽  
Patrick J. Breen
Keyword(s):  
High Light ◽  
Thermal Dissipation ◽  
Photochemical Quenching ◽  
Light Conditions ◽  
Psii Efficiency ◽  
Fluorescence Measurements ◽  
Free Radical Formation ◽  
Highly Correlated ◽  
Non Photochemical Quenching ◽  
Leaf N

Bench-grafted Fuji/M26 apple trees were fertigated with different concentrations of nitrogen by using a modified Hoagland solution for 6 weeks, resulting in a range of leaf N from 1.0 to 4.3 g·m–2. Over this range, leaf absorptance increased curvilinearly from 75% to 92.5%. Under high light conditions (1500 (mol·m–2·s–1), the amount of absorbed light in excess of that required to saturate CO2 assimilation decreased with increasing leaf N. Chlorophyll fluorescence measurements revealed that the maximum photosystem II (PSII) efficiency of dark-adapted leaves was relatively constant over the leaf N range except for a slight drop at the lower end. As leaf N increased, non-photochemical quenching under high light declined and there was a corresponding increase in the efficiency with which the absorbed photons were delivered to open PSII centers. Photochemical quenching coefficient decreased significantly at the lower end of the leaf N range. Actual PSII efficiency increased curvilinearly with increasing leaf N, and was highly correlated with light-saturated CO2 assimilation. The fraction of absorbed light potentially used for free radical formation was estimated to be about 10% regardless of the leaf N status. It was concluded that increased thermal dissipation protected leaves from photo-oxidation as leaf N declined.

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